In a Signaling System #7 (SS7) network, both ANSI and Telcordia standards recommend implementation of the optional Hop Counter parameter in the ISDN User Part (ISUP) Initial Address Message (IAM) as a procedure to detect call routing loops caused by Common Channel Signaling Switching Office (CCSSO) translation errors. In situations where carriers decide to implement the Hop Counter only as an intra-network procedure, and not as an inter-network procedure, the Hop Counter procedure then can only be used to detect intra-network routing loops. In these scenarios, inter-network routing loops cannot be detected and these calls will generate additional signaling traffic that can aggregate to overload signaling networks.
Therefore, a need exists for a method to reliably detect inter-network routing loops and kill associated calls using a modified ISUP Hop Counter parameter to be sent across network boundaries.